Mercedes-Benz B-Class Starter Motor Replacement Parts

The B-Class has run across two main generations: the W245 (2005–2011) and the W246 (2012–2018, facelifted in 2015), and starter motors do not generally cross between these generations due to different engine families. Within the same generation, fitment is driven primarily by engine code rather than model year alone, so a W246 motor from a 2013 car may or may not suit a 2016 facelift car even with the same badge on the boot — confirm the engine code from your V5 or a VIN check, then let your breaker match it precisely. Never assume fitment across the W245/W246 boundary without confirming with the breaker against your registration.

Yes — petrol and diesel engines have different starter motor specifications, so a diesel unit from a B200 CDI will not be a straight swap onto a petrol B200 even within the same generation. The engine code is the most reliable guide here: codes such as OM651 indicate a diesel where codes like M270 indicate a petrol, and your breaker needs that code to source the correct unit. Always supply your engine code rather than just the fuel type badge when requesting a quote.

No, trim level does not affect starter motor fitment on the B-Class. Whether your car is a Sport, SE, AMG Line, or any other trim, what matters mechanically is the engine code, fuel type, and gearbox type — the trim name only dictates interior and cosmetic differences. Give your breaker your engine code and they will identify the correct unit regardless of which trim badge your car carries.

Gearbox type can affect the starter motor specification because the ring gear on the flywheel (manual) or flexplate (automatic) may differ in tooth count or diameter, which changes the pinion engagement requirements. It is worth telling your breaker whether your car has a manual or the 7G-DCT dual-clutch automatic, as this can influence which units are compatible. Confirm this detail alongside your engine code when requesting a quote to avoid an incompatible part.

The W246 facelift in 2015 brought some engineering updates, and while starter motor fitment within the same engine code is often consistent across the facelift boundary, ancillary mounting and specification changes mid-production mean this cannot be guaranteed. The engine code is your best starting point — if the donor and recipient car share the same code, there is a reasonable chance of compatibility, but you should still confirm with the breaker against both registrations before purchasing. Do not assume cross-facelift interchangeability without that check.

Most B-Class variants across both the W245 and W246 generations use a conventional electromagnetic starter motor, so this is a genuine and commonly replaced part on this model. However, some later W246 models with the ECO start-stop system may use an enhanced-duty or higher-torque starter motor to handle the increased cycling demands, which means specification can vary even within the same engine family. Confirm your exact engine code and whether your car has start-stop when requesting a quote, and note that starter motors may require coding or compatibility checks with the vehicle's immobiliser system — your breaker can advise on this.